Creating ROS1 Action

Below are the steps to create a ROS1 action:

Step 1: Add the following in package.xml

roscpp # Use this if the action is in C++
rospy # Use this if the action is in Python
actionlib
std_msgs
message_generation
actionlib_msgs
roscpp # Use this if the action is in C++
rospy # Use this if the action is in Python
actionlib
std_msgs
message_runtime
actionlib_msgs

Step 2: Add the following in CMakeLists.txt

find_package(catkin REQUIRED COMPONENTS
roscpp # Use this if the action is in C++
rospy  # Use this if the action is in Python
std_msgs
message_generation
actionlib_msgs
actionlib
)

add_action_files(FILES ActionFile.action)

generate_messages(DEPENDENCIES actionlib_msgs std_msgs)

catkin_package(
LIBRARIES action_name
CATKIN_DEPENDS std_msgs actionlib_msgs actionlib roscpp
)

include_directories(${catkin_INCLUDE_DIRS})

# SKIP ALL BELOW IF THE ACTION SERVER & CLIENT ARE WRITTEN IN PYTHON

add_executable(action_server src/action_server.cpp)
add_dependencies(action_server ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
target_link_libraries(action_server ${catkin_LIBRARIES})

add_executable(action_client src/action_client.cpp)
add_dependencies(action_client ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
target_link_libraries(action_client ${catkin_LIBRARIES})

Step 3: Create a folder called “action” (if you still don’t have it) inside your package folder. And then make the action file (.action) called “ActionFile.action”. For example, if the action is to compute Fibonacci numbers, you may call it “Fibonacci.action” which looks like below:

#goal definition
int32 order
---
#result definition
int32[] sequence
---
#feedback
int32[] sequence

The lines of three dashes above separate between the request variable(s), the result variable(s), and the feedback variable(s).

Step 4: Write the “action_server” node.

Using C++, write the action_server node in a file namely “action_server.cpp”, inside “src” folder of the package. An code example can be found here: http://wiki.ros.org/actionlib_tutorials/Tutorials/SimpleActionServer%28ExecuteCallbackMethod%29

Using Python, write the action_server node in a file namely “action_server.py”, inside “script” folder of the package. An code example can be found here: http://wiki.ros.org/actionlib_tutorials/Tutorials/Writing%20a%20Simple%20Action%20Server%20using%20the%20Execute%20Callback%20%28Python%29

Step 5: Write the “action_client” node.

Using C++, write the action_client node in a file namely “action_client.cpp”, inside “src” folder of the package. An code example can be found here: http://wiki.ros.org/actionlib_tutorials/Tutorials/SimpleActionClient

Using Python, write the action_client node in a file namely “action_server.py”, inside “script” folder of the package. An code example can be found here: http://wiki.ros.org/actionlib_tutorials/Tutorials/Writing%20a%20Simple%20Action%20Client%20%28Python%29

Step 6: Build the package by using “catkin_make” command.

Running the action

After making sure that ROS Master is running (unless roslaunch is used), type the following in the terminal to run the “action_server” node:

For C++ action: rosrun package_name action_server
For Python action: rosrun package_name action_server.py

To call the action, run the “action_client” node:

For C++ action: rosrun package_name action_client
For Python action: rosrun package_name action_client.py

To show the stream of the action feedback:

rostopic echo /action_name/feedback